1. Field of the Invention
The present invention provides a reticle transferring support for containing a reticle, and more particularly to a reticle transferring support that can avoid damaging the reticle.
2. Description of the Prior Art
Photolithography is an important step in the entire processes of semiconductor production. Characteristics associated with MOS transistors, such as film pattern or dopant region, are determined by this step. Photolithography basically proceeds by covering a layer of photo-sensitive material on a semiconductor, and casting a parallel light beam, through a reticle, onto the photosensitive material. Since the reticle has patterns of a circuit layout, the photo-sensitive material incurs a selective photo reaction so that the pattern on the reticle will be transferred to the semiconductor wafer.
In general, the reticle comprises a smooth and transparent plate of glass or quartz as its foundation, and a layer of chromium film of 1000 Å thick over the surface of the reticle. Therefor the pattern on the reticle is very fragile.
Please refer to FIG. 1 and FIG. 2. FIG. 1 is a top view of a reticle transferring support of a SMIF pod in the prior art. FIG. 2 is a cross-section diagram of a reticle transferring support of a SMIF pod in the prior art. As shown in FIG. 1, the reticle transferring support 10 comprises a supporting base 12 having four rectangular braces 14 for supporting a reticle 16. For conforming to the semiconductor and material international (SEMI) standard, both sides of the reticle transferring support have to keep a gap of 0.95 mm for the convenience of reticle load/unload. However, it is not easy to fix the position of the reticle when the operator places the reticle 16 with a reticle clip into the reticle transferring support 10. Particularly, if the position of the reticle 16 deviates too much, errors could happen in the following vacuum adsorption operation.
Therefore the operator needs to adjust the reticle 16 to proper position. However, it is not easy to adjust the position of the reticle 16 manually, besides, damages of the reticle 16 are often caused by friction during the reticle adjusting action. As shown in FIG. 2, the braces 14 of the reticle transferring support 10 have a rectangular structure, thus the contact area between the reticle 16 and the braces 14 is wide, which makes it easy to damage a bar code area (not shown) and a vacuum adsorption area (not shown) of the reticle 16.
Please refer to FIG. 3. FIG. 3 is a flow chart of a reticle transferring procedure according to the prior art. As shown in FIG. 3, the reticle transferring procedure comprises following steps: Step 30: start; Step utilize an opener to open a SMIF pod; Step 34: utilize a reticle clip to place a reticle into a reticle transferring support of the SMIF pod; Step 36: adjust the position of the reticle; Step 38: utilize the opener to close the SMIF pod; and Step 40: end.
In the reticle transferring procedure of the prior art, first an opener as Asyst ALU opener) is employed to open a SMIF pod. Then a reticle is manually placed in a reticle transferring support of the SMIF pod by a reticle clip, and adjusted to proper position. Finally, the SMIF pod is closed by the opener. As mentioned above, the reticle transferring support 10 of the SMIF pod has to keep a gap of 0.95 mm on both sides for conforming to the SEMI standard, and moreover the contact area between the reticle 16 and the rectangular braces 14 is too wide, thus the back surface of the reticle 16 is easily damaged. For this reason, a reticle transferring support that can avoid damaging the reticle is eagerly required.